The researchers, who recently published a review of the current state of gas-detecting stretchable sensors, say their work could help advance sensors used to monitor gaseous biomarkers in humans and toxic gas in an exposed environment. Recent developments in gas-sensing technologies have made it possible to detect gaseous biomarkers in humans by monitoring the metabolic process through exhaled breath or skin perspiration and detect harmful or toxic gases in humans’ surrounding environment.
However, human motions that significantly stretch the skin can degrade or deform the sensors, making them unable to detect gases accurately. To make a more resilient sensor, say the researchers, they have investigated the most effective sensor fabrication methods that could work for a variety of applications.
"With recent developments in breath analysis," says Huanyu "Larry" Cheng, Dorothy Quiggle Career Development Professor in the Penn State Department of Engineering Science and Mechanics, "we are starting to build momentum toward developing a gas sensor that could have a larger platform of applications."
Such gas sensors, say the researchers, can help provide an earlier medical diagnosis by detecting volatile organic compounds (VOCs) from human breath, which may indicate the presence of several diseases, including amoebic dysentery, intestinal bacterial infections, and cancer. Previous sensors could only monitor glucose and pH levels.
"From human skin perspiration and the exhaled breath, we have about 2,600 biomarkers in the gas form," says Cheng. "This gives us vital information that we can leverage in the development of disease diagnostics."
In addition to monitoring these biomarkers, the sensors can detect dangerous levels of toxic gases that may be present in a surrounding environment. For example, the sensors could detect dangerous levels of methane in coal mines and potentially monitor the health and safety of coal miners.
While current gas sensors have similar characteristics to the versions being studied, say the researchers, they have flaws. For example, metal oxide-based gas sensors have high working temperatures, making them